The story

When cancer invades the brain, the prognosis is usually grim. Despite his treatment at highly regarded medical centers, Edward "Ted" Kennedy, who served as a Democratic senator from Massachusetts for nearly 47 years, died just over a year after his surgery.

Kennedy suffered a seizure May 17, 2008, while walking his dogs at his home in Hyannis Port. Three days later, doctors at Massachusetts General Hospital in Boston said a brain biopsy revealed a tumor, known as a malignant glioma, in the left parietal lobe.

Malignant gliomas are the second-most common cause of death from cancer for people 15 to 44 years old, according to a 2005 study in the Journal of the American Medical Association.

The causes of glioma tumors are mysterious. Many patients do not have genetic risk factors, and any connections with lifestyle are not clear, said Dr. Larry Junck, head of the Neuro-Oncology Program at the University of Michigan Comprehensive Cancer Center. Junck was not involved in the senator's treatment.

Gliomas do not often spread to other parts of the body, but grow into the brain at their site of origin, Junck said. Read full article »